A method for operating a measuring device having at least one measured value sensor for recording and forwarding measured values of a primary measured variable. To ensure a particularly high reliability and measuring accuracy, the recording of the measured value and/or the forwarding of the measured value is carried out in dependence on the operating state of the measuring device, recording of the measured value and/or the forwarding of the measured value being interrupted during a disturbance. The measuring device is wherein the measured value sensor is designed in such a manner that the recording of the measured value and/or the forwarding of the measured value is carried out in dependence on the operating state of the measuring device, wherein the recording of the measured value or the forwarding of the measured value is interrupted during a disturbance.

In one example a fluid level sensing device is described. The device includes a sensing die having a number of fluid level sensors disposed thereon and a number of control devices, each control device corresponding to one of the number of fluid level sensors. A control device includes a comparing device to determine a state of a corresponding fluid level sensor. A state of the fluid level sensor is selected from the group consisting of a fluid state and a no fluid state. Each control device also includes a non-volatile memory device corresponding to the comparing device to indicate whether the corresponding fluid level sensor is at the fluid state or the no fluid state. A control device also includes a locking device to receive a write command and to irreversibly set the non-volatile memory device to the no fluid state based on the write command.

In one example a fluid level sensing device is described. The device includes a sensing die having a number of fluid level sensors disposed thereon and a number of control devices, each control device corresponding to one of the number of fluid level sensors. A control device includes a comparing device to determine a state of a corresponding fluid level sensor. A state of the fluid level sensor is selected from the group consisting of a fluid state and a no-fluid state. Each control device also includes a non-volatile memory device corresponding to the comparing device to indicate whether the corresponding fluid level sensor is at the fluid state or the no-fluid state. A control device also includes a locking device to irreversibly set the non-volatile memory device to the no-fluid state independent of a write command from a controller.

A method and system are described for detecting a fault of a fluid level sensing device associated with an aircraft engine, the fluid level sensing device arranged to measure a variance in a fluid level. The method comprises triggering a timer, while the timer is running, receiving a measurement indicative of the fluid level from the fluid level sensing device, resetting the timer when at least one timer-reset condition has been met, and outputting a fault signal when the timer reaches a timer threshold.

A method for checking the functional ability of an FMCW-based fill-level measuring device, which serves for measuring the fill level of a fill substance located in a container, as well as to a fill-level measuring device suitable for performing this method. For checking the functional ability, a microwave signal is produced, whose frequency change differs from the frequency change of the measurement signal used during regular measurement operation. By comparing the frequency of the difference signal resulting from the microwave signal with a predetermined reference frequency, it is ascertained, whether the fill-level measuring device is functionally able. Thus, the fill-level measuring device detects, independently, whether it is functionally able, or whether an error is present, caused principally by device-internal disturbance signals. This offers, especially, a clear advantage as regards meeting safety standards for the field device.

Disclosed is a method for diagnosis of a two-conductor field instrument and a corresponding two-conductor field instrument. In a normal operating mode, an input voltage is provided and an output current is output. In a diagnostic operating mode, the method includes: providing a first diagnosis-input voltage and outputting a first diagnosis-output current during a first time interval, providing a second diagnosis-input voltage and outputting a second diagnosis-output current during a second time interval, determining the second time interval from the first time interval, registering a first and second diagnosis-output voltage as a function of the first and second diagnosis-output current, and checking the functionality of the two-conductor field instrument by the first and second diagnosis-input voltage, the first and second time interval, the first and second diagnosis-output electrical current, the first and second diagnosis-output voltage based on the input voltage and/or based on the output electrical current.

A radiometric measuring apparatus detects a measured variable in the form of a fill level, a point level, a density and/or a mass flow, and includes a scintillator embodied to generate light pulses upon excitation by ionizing radiation, an optoelectronic sensor embodied to convert the light pulses into a sensor signal, a first signal processing unit embodied to process the sensor signal into a first measured variable signal, an adjustable second signal processing unit embodied in a measurement setting to process the sensor signal into a second measured variable signal, wherein the second measured variable signal corresponds to the first measured variable signal in the case of a correctly processing first signal processing unit and a correctly processing second signal processing unit, and embodied in at least one operation setting to process the sensor signal into at least one operating variable signal, wherein the at least one operating variable signal does not correspond to the measured variable signals, a setting unit embodied to set the second signal processing unit into the measurement setting in measured variable time intervals and into the at least one operation setting in operating variable time intervals that alternate with the measured variable time intervals, and an assessment unit embodied to compare the first measured variable signal and the second measured variable signal with one another and to assess the first signal processing unit and/or the second signal processing unit to be processing correctly or incorrectly, depending on a result of the comparison.

The present disclosure relates to a method for testing a brake fluid sensor of a vehicle braking system, wherein the brake fluid sensor can indicate the fluid level in the fluid reservoir, wherein the method has the following steps: (1) Altering the fluid level in at least one region of the at least one fluid reservoir by means of at least one braking force generating device; and (2) Detecting whether the at least one brake fluid sensor emits a signal indicating the modified fluid level in the at least one region of the at least one fluid reservoir.

The application discloses a method for verifying the accuracy of a guided-wave radar measuring device used in process automation. The method includes sending measuring radar waves to a built-in verification circuit of a known and verified length and performing time-of-flight analysis on the measuring radar wave reflected by the built-in verification circuit. The application also discloses a guided-wave radar device having a built-in verification circuit.

A fuel cell system includes a fuel cell stack, a gas liquid separator, a water level sensor, a drain valve, and a control unit. When a failure detection processing method is performed, a control unit makes a determination of main conditions where the water level sensor determines that water is present, a power generation current value of the fuel cell stack is not more than a predetermined current threshold value, a drain valve for discharging water in the gas liquid separator is open. Then, the control unit counts elapsed time when the main conditions are satisfied, and in the case where the main conditions are kept satisfied for the elapsed time which is larger than a time threshold value, the control unit determines that the water level sensor has a failure.